Clean the skin of potato; boiled it into a pot until soft; using the mortar and pestle to mash the potato to smooth; with low heat, put potato and cream, a dash salt and pepper into a pot; using a wooden spoon to stir it till smooth.

Blend the ginger to get the juice, soak the tuna eye inside it. Blanching it in boiled water to reduce the bad smell. Add in congee stock with mix mushroom, seasoning with chicken powder and fish sauce. Add spring onion and coriander when serving.